The blast left body parts strewn around the area, said Moetez al-Agouri, a police officer at the post, and the death toll was likely to rise.

“Seven bodies among the victims have been identified but some other bodies were torn to pieces by the explosion,” said Agouri, who was working at the checkpoint at the time but escaped injury.

Eight people including civilians were wounded in the attack on the checkpoint 50 kilometres east of Benghazi and were taken to hospital in the nearby town of Tokra, Agouri said.

The security post's chief, Fraj al-Abdelli, who was wounded in the attack, said the checkpoint had received several threats since arresting four people in November who were carrying weapons, explosives, money and a hit-list.

He said a police convoy transporting the suspects to a Benghazi barracks after their arrest came under attack as it entered the city.

Four soldiers were killed and three wounded in that attack, he said.

Benghazi, the cradle of the 2011 uprising that toppled long-time dictator Moamer Kadhafi, has seen a series of attacks in recent months that have killed more than 300 people.

Knife-wielding protesters stormed the headquarters of Libya's largest telecoms provider and forced an eight-hour shutdown.

Dozens of people calling for Prime Minister Ali Zeidan to resign occupied the Libyan Telecom and Technology (LTT) HQ in eastern Tripoli.

The service was down for about eight hours.

In addition to calling for Zeidan's ouster, the group condemned the blockade of vital oil terminals in the east, LTT communications chief Mourad Bilal said.

Oil Minister Abdelbari al-Arusi on Saturday issued a renewed threat of force to lift the blockade.

“The government is making every effort to hold talks with those blockading the terminals,” he told journalists on the sidelines of a conference in Doha of the Organisation of Arab Oil Exporting Countries.